Delineation of potential groundwater zones based on multicriteria decision making technique

Groundwater is the most prioritized water source in India and plays an indispensable role in India’s economy. The groundwater potential mapping is key to the sustainable groundwater development and management. A hybrid methodology is applied to delineate potential groundwater zones based on remote sensing, geographical information systems(GIS) and analytic hierarchy process(AHP) as on multicriteria decision making. For the purpose of demonstrating field application, Chittar watershed, Tamilnadu, India is studied as an example. The important morphological characteristics considered in the study are lithology, geomorphology, lineament density, drainage density, slope, and Soil Conservation Service–Curve Number(SCS-CN). These six thematic layers are generated in a GIS platform. Based on intersecting the layers, AHP method, the values for adopting the pairwise comparison normalized weight and normalized subclasses weightage were given. The normalized subclass weightage is input into each layer subclass. Then, weighted linear combination method is used to add the data layers in GIS platform to generate groundwater potential Index(GWPI) map. The GWPI map is validated based on the net recharge computed from the differences of measured groundwater levels between the pre-monsoon and post-monsoon in the year 2018. The kappa statistics are used to measure level spatial consistency between the GWPI and net recharge map. The overall average spatial matching accuracy between the two data sets is 0.86, while the kappa coefficient for GWPI with net recharge, 0.78. The results show that in Chittar watershed about 870 km^2 area is divided into high potential zone(i.e. sum of very high and high potential zone), 667 km^2 area, as the moderate one and the rest 105 km^2 area, as the poor zone(i.e. sum of very poor and poor potential zone).

Delineation of groundwater potential zones in Theni district,Tamil Nadu,using remote sensing,GIS and MIF techniques

Integration of remote sensing data and the geographical information system （GIS） for the exploration of groundwater resources has become a breakthrough in the field of groundwater research, which assists in assessing, monitoring, and conserving groundwater resources. In the present paper, various groundwater potential zones for the assessment of groundwater availability in Theni district have been delineated using remote sensing and GIS techniques. Survey of India toposheets and IRS-IC satel- lite imageries are used to prepare various thematic layers viz. lithology, slope, land-use, lineament, drainage, soil, and rainfall were transformed to raster data using feature to raster converter tool in ArcGIS. The raster maps of these factors are allocated a fixed score and weight computed from multi influencing factor （MIF） technique. Moreover, each weighted thematic layer is statistically computed to get the groundwater potential zones. The groundwater potential zones thus obtained were divided into four categories, viz., very poor, poor, good, and very good zones. The result depicts the groundwater potential zones in the study area and found to be helpful in better planning and management of ground- water resonrces.

Mapping favorable groundwater potential recharge zones using a GIS-based analytical hierarchical process and probability frequency ratio model:A case study from an agro-urban region of Pakistan

In Punjab(Pakistan),the increasing population and expansion of land use for agriculture have severely exploited the regional groundwater resources.Intensive pumping has resulted in a rapid decline in the level of the water table as well as its quality.Better management practices and artificial recharge are needed for the development of sustainable groundwater resources.This study proposes a methodology to delineate favorable groundwater potential recharge zones(FPRI)by integrating maps of groundwater potential recharge index(PRI)with the DRASTIC-based groundwater vulnerability index(VI).In order to evaluate both indexes,different thematic layers corresponding to each index were overlaid in ArcGIS.In the overlay analysis,the weights(for various thematic layers)and rating values(for sub-classes)were allocated based on a review of published literature.Both were then normalized and modified using the analytical hierarchical process(AHP)and a frequency ratio model respectively.After evaluating PRI and FPRI,these maps were validated using the area under the curve(AUC)method.The PRI map indicates that 53%of the area assessed exists in very low to low recharge zones,22%in moderate,and 25%in high to excellent potential recharge zones.The VI map indicates that 38%of the area assessed exists in very low to low vulnerability,33%in moderate,and 29%in high to very high vulnerability zones.The FPRI map shows that the central region of Punjab is moderately-to-highly favorable for recharge due to its low vulnerability and high recharge potential.During the validation process,it was found that the AUC estimated with modified weights and rating values was 79%and 67%,for PRI and VI indexes,respectively.The AUC was less when evaluated using original weights and rating values taken from published literature.Maps of favorable groundwater potential recharge zones are helpful for planning and implementation of wells and hydraulic structures in this region.

Optimizing groundwater recharge plan in North China Plain to repair shallow groundwater depression zone, China

The North China Plain is one of the main grain producing areas in China. However, overexploitation has long been unsustainable since the water supply is mainly from groundwater. Since 2014,the South-to-North Water Diversion Project's central route has been charted to the integrated management of water supply and over-exploitation, which has alleviated the problem to a certain extent. Although the Ministry of Water Resources has made many efforts on groundwater recharge since 2018 most of which have been successful, the recharge has not yet been sufficiently focused on the repair of shallow groundwater depression zones. It still needs further optimization. This paper discusses this particular issue,proposes optimized recharge plan and provides the following recommendations:(1) Seven priority target areas are selected for groundwater recharge in alluvial and proluvial fans in the piedmont plain, and the storage capacity is estimated to be 181.00×10~8 m~3;(2) A recharge of 31.18×10~8 m~3/a is required by 2035 to achieve the repair target;(3) It is proposed to increase the recharge of Hutuo River, Dasha River and Tanghe River to 19.00×10~8 m~3/a and to rehabilitate Gaoliqing-Ningbailong Depression Zone;increase the recharge of Fuyang River, Zhanghe River and Anyang River to 7.05×10~8 m~3/a and rehabilitate Handan Feixiang-Guangping Depression Zone;increase the recharge of Luanhe River by 0.56×10~8 m~3/a and restore Tanghai Depression Zone and Luanan-Leting Depression Zone;moderately reduce the amount of water recharged to North Canal and Yongding River to prevent excessive rebound of groundwater;(4) Recharge through well is implemented on a pilot basis in areas of severe urban ground subsidence and coastal saltwater intrusion;(5) An early warning mechanism for groundwater quality risks in recharge areas is established to ensure the safety. The numerical groundwater flow model also proves reasonable groundwater level restoration in the depression zones by 2035.

Integration of geoelectric and hydrochemical approaches for delineation of groundwater potential zones in alluvial aquifer

Geoelectric and hydrochemical approaches are employed to delineate the groundwater potential zones in District Okara,a part of Bari Doab,Punjab,Pakistan.Sixty-seven VES surveys are conducted with the Electrical Resistivity Meter.The resultant resistivity verses depth model for each site is estimated using computer-based software IX1D.Aquifer thickness maps and interpreted resistivity maps were generated from interpreted VES results.Dar-Zarrouk parameters,transverse resistance(TR),longitudinal conductance(SL)and anisotropy(λ)were also calculated from resistivity data to delineate the potential zones of aquifer.70%of SL value is≤3S,30%of SL value is>3S.According to SL and TR values,the whole area is divided into three potential zones,high,medium and low potential zones.The spatial distribution maps show that north,south and central parts of study area are marked as good potential aquifer zones.Longitudinal conductance values are further utilized to determine aquifer protective capacity of area.The whole area is characterized by moderate to good and up to some extent very good aquifer protective area on the basis of SL values.The groundwater samples from sixty-seven installed tube wells are collected for hydro-chemical analysis.The electrical conductivity values are determined.Correlation is then developed between the EC(μS/cm)of groundwater samples vs.interpreted aquifer resistivity showing R2 value 0.90.

Mapping of groundwater potential zones in the drought-prone areas of south Madagascar using geospatial techniques

The southern regions of Madagascar have the country’s lowest water supply coverage and are highly vulnerable to drought.Access to potable drinking water is a major challenge for the local population.Chronic droughts lead to annual emergency appeals to save the lives of acute malnourished children.UNICEF’s response consisting in providing potable drinking water through the drilling of boreholes has been challenged by the complex hydrogeology,the low yield of boreholes and high-level salinity of water,the lack of reliable groundwater data and the weak capacity of the drilling sector.These constraints result in a high rate of drilling failure.To improve drilling success and provide more potable drinking water to local communities,it is vital to undertake reliable groundwater investigation.UNICEF Madagascar and the European Union delegation in Madagascar collaborated on the use of satellite imagery to improve sector knowledge and access to safe and clean water for local communities in southern Madagascar.The methodology relies on produce thematic layers of groundwater potential areas.Later,these thematic layers were overlaid with ground-based hydrogeological data to map the groundwater potential zones(GWP) and identify the most suitable sites for borehole siting and drilling.Findings of this study are very encouraging,and the integrated approach used has proven its applicability in mapping groundwater potential areas in the eight drought-affected areas of south Madagascar.The groundwater potential zone map is being used by UNICEF and partners to plan water supply projects and identify the best sites for positioning new boreholes and reduce the likelihood of drilling failure.Additionally,the project developed a database of groundwater resources,which will improve knowledge of the regional hydrogeological context and strengthen the capacity of the water sector.Lessons learnt from this study show that an integration of the groundwater potential zone map with demographics and water demand information will help identifying priority areas for detailed studies.Moreover,a capacity building activity is required for knowledge/technology transfer to the Ministry of Energy,Water and Hydrocarbons(MEEH),allowing the possibility of scaling-up this integrated approach to the rest of Madagascar.Finally,strengthening the capacity of the MEEH and refining this approach as suggested above will certainly help in the pursuit to improve equitable access to safe and clean water for households located in the drought-affected areas of southern Madagascar,allowing them to be more resilient to the effects of climate change.

Application of GIS based analytical hierarchy process and multicriteria decision analysis methods to identify groundwater potential zones in Jedeb Watershed, Ethiopia

The hydrogeological situation of the study area requires the identification of groundwater potential.Remote sensing and satellite data have proven to be reliable tools for understanding various factors that affect groundwater occurrence and movement.This study employed weighted overlay analysis based on satellite imagery and secondary data to create a thematic map for characterizing groundwater potentials in the study area located within Abbay Basin,Ethiopia.Remote sensing(RS)and GIS-based Fuzzy-Analytical Hierarchy Process methods were utilized to classify groundwater potential(GWP)zones into five categories:Very good,good,moderate,poor,and very poor.The central and eastern parts of the study area were identified as having high(33.186%)and very high(2.351%)groundwater potentials,while the western part exhibited poor and very poor potential areas.The groundwater potential map delineated higher and moderate potentials,suitable for installing shallow and production bores.This research demonstrates the effectiveness of RS and GIS techniques for delineating groundwater potential zones,which can aid in the planning and management of groundwater resources.The research findings have the potential to contribute to the formulation of improved groundwater management programs in the study area.

Research on groundwater ecological environment mapping based on ecological service function:A case study of five Central Asian countries and neighboring regions of China

The groundwater system is a unique ecosystem that serves both resource and ecological functions.Hydrogeologists have conducted extensive theoretical research and practical work on groundwater ecological mapping.This paper,based on the study of groundwater resources and surface ecology in the five Central Asian countries and adjacent areas of China,introduces the concept of ecosystem service functions.It establishes a groundwater ecological zoning index system and conducts research of ecological mapping using the five Central Asian countries and adjacent areas of China as examples.Through this process,the ecosystem service functions of groundwater can be more comprehensively reflected,which can better guide regional geological environment protection and industrial planning.This approach helps coordinate the relationship between socio-economic development and water resource protection,maintain the health of the groundwater ecological environment,enhance the value of groundwater ecological services,and promote the sustainable development of regional economies and societies.

Upgrading a regional groundwater level monitoring network for Beijing Plain,China

Monitoring of regional groundwater levels provides important information for quantifying groundwater depletion and assessing impacts on the environment. Historically, groundwater level monitoring wells in Beijing Plain, China, were installed for assessing groundwater resources and for monitoring the cone of depression. Monitoring wells are clustered around well fields and urban areas. There is urgent need to upgrade the existing monitoring wells to a regional groundwater level monitoring network to acquire information for integrated water resources management. A new method was proposed for designing a regional groundwater level monitoring network. The method is based on groundwater regime zone mapping. Groundwater regime zone map delineates distinct areas of possible different groundwater level variations and is useful for locating groundwater monitoring wells. This method was applied to Beijing Plain to upgrade a regional groundwater level monitoring network.

Petroleum Pollution of Groundwater in Zibo and Its Prevention Measures

The source of ground water supply in Dawu is an extremely huge one in Shandong province. Now it is faced with serious pollution of petroleum in Hougao area. Aiming at this problem, the petroleum pollution in aeration zone and in groundwater was analyzed. The result shows that the contaminant of groundwater comes from the leaching of petroleum in the soil horizon of aeration zone through precipitation, and the quick flow of groundwater makes the convection dominate themigration of contaminant. So movement of groundwater controls the distribution of petroleum contaminant, which is consistent with the direction of ground flow. Building a groundwater closure zone in Hougao is an effective method to stop the contaminated groundwater flowing toward the water supply source of Dawu. The petroleum contaminant can be effectively reduced through using the aeration, biological and oxidation technologies.

Groundwater protection:What can we learn from Germany?

For drinking water security the German waterworks proceed on a comprehensive concept,i.e.,the protection of all the regions from the recharge area to the client.It includes the protection of the recharge area by a precautionary management,a safe water treatment,a strict maintenance of the water distribution network,continuous control and an intensive training of staff.Groundwater protection zones together with effective regulations and control play a very important role.Three protection zones with different restrictions in land-use are distinguished.Water in reservoirs and lakes is also protected by Surface Water Protection Zones.Within the surrounding area the land-use is controlled,too.Special treatment is necessary if acidification happens caused by acid rain,or eutrophication caused by the inflow of sewage.Very important is the collaboration between waterworks and the farmers cultivating land in the recharge area in order to execute water-protecting ecological farming with the aim to reduce the application of fertilizers and plant protection agents.Probable financial losses have to be compensated by the waterworks.

Determination of groundwater potential distribution in Kulfo-Hare watershed through integration of GIS, remote sensing, and AHP in Southern Ethiopia

Identification of groundwater potential areas(GPA)is important in regions facing surface water scarcity,as it assists in effective planning and utilization of groundwater for various purposes.This study employs the methods of remote sensing(RS),geographic information system(GIS)model,and analytical hierarchy process(AHP),multi-criteria decision analysis(MCDA)to locate and map the prospective groundwater areas in the Kulfo-Hare watershed.Seven significant groundwater influencing factors were selected for the determination of groundwater potential in the area:Geology,land use/land cover(LULC),soil,rainfall,slope,drainage density,and lineament density.By applying a five-class classification scheme(very low,low,moderate,high,and very high),the GIS models were used to define the distribution of groundwater potential areas in terms of area coverage(km^(2)),percentage and mapping.The results show that the groundwater potential(GWP)distribution in the research region is as follows:9.7%(6035.9 ha)classified as very high GWP,29.6%(18606 ha)classified as high,24.5%(15245 ha)classified as moderate,18.1%(11431 ha)as low and 18.1%(11492 ha)very low GWP,on the basis of the weighted overlay evaluation.Although a few regions are identifies as extremely low GWP,most of the study area is characterized by very high to moderate GWP.These findings provide valuable insight for sustainable groundwater planning by the government bodies,decision-makers,and private sectors.

Groundwater Exploration Using Multi Criteria Decision Analysis and Analytic Hierarchy Process in Federal Capital Territory, Abuja, Central Nigeria

There exists a growing demand for potable water resources to fill the abysmally insufficient water needs for domestic and industrial especially in the Basement Complex terrains of Nigeria. This situation is attributable to its complex hydrogeologic character. The present challenge has worsened due to the non-incorporation of integrated methods in groundwater exploration campaigns. To effectively combat the challenge of unacceptable failure rates in drilled water well development, there is a need for innovative scientific principles and quantitative assessment of groundwater resources to enhance sustainable and proper utilisation of these resources. Hence, it is the objective of this research to exploit the potential application of remote sensing, Geographic Information System (GIS), and Multi-Criteria Decision Analysis (MCDA) techniques and freely open datasets in mapping groundwater potential zones. Seven thematic maps have been produced based on factors that are deemed to influence and deemed to have significant control on the occurrence and movement of groundwater. These factors are geology, lineament density, slope, drainage density, rainfall, land-use/land cover, and soil class. Analytic Hierarchy Process (AHP) was used to assign normalised weights to the thematic maps based on the various relative contributions to groundwater occurrence and movement. These thematic maps were then processed in a GIS environment using the Weighted Overlay tool which implements the MCDA. The resulting Groundwater Potential Zones (GPZ) of the area gave rise to Five classes viz: Very good, Good, Moderate, Poor and Very Poor representing 19%, 8%, 14%, 47% and 13% respectively. It is recommended that the GPZ map should be used as a reconnaissance tool for selecting prospective sites for detailed groundwater resource exploitation.